var div = document.getElementsByClassName('game')[0];
var startPoint = {x : 0}
var endPoint = {x : 0}

var xx= $('.content_mid').width();
div.ontouchstart = function(event){
    var touchST = event.changedTouches[0];
    startPoint.x = touchST.pageX;
}
div.ontouchmove = function(event){
    var touchED = event.changedTouches[0];
    endPoint.x = touchED.pageX;
    var ss=div.offsetLeft + endPoint.x - startPoint.x;
   
    console.log(event)
    if (ss<0&&ss>-xx) {
     div.style.left =ss + "px";
    }
  
    startPoint.x = endPoint.x;
    event.preventDefault();
    return false;
}